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#include "project.h"
#define OT_THM_IN GPIO6
#define OT_THM_IN_PORT GPIOB
#define OT_BLR_IN GPIO7
#define OT_BLR_IN_PORT GPIOB
#define OT_RX_IRQ NVIC_EXTI9_5_IRQ
typedef struct rx_phy {
uint32_t last_cycle;
int last_v;
unsigned half_bits;
unsigned data_bits;
int frame_error;
uint8_t data[10];
int parity;
} RX_Phy;
static RX_Phy p_thm, p_blr;
static uint32_t
cycle_diff (uint32_t a, uint32_t b)
{
return b - a;
}
static void ot_phy_rx_bit (RX_Phy *p)
{
if (p->half_bits & 1)
p->frame_error = 1;
if (!p->half_bits) {
if (!p->last_v)
p->frame_error = 1;
return;
}
if (p->data_bits < 32) {
if (p->last_v) p->data[p->data_bits >> 3] |= 0x80 >> (p->data_bits & 7);
p->parity ^= p->last_v;
} else if (p->data_bits == 32) {
if ((!p->last_v) || (p->parity))
p->frame_error = 1;
led_blink();
if (p == &p_thm)
ot_rx_thm (p->data, p->frame_error);
else
ot_rx_blr (p->data, p->frame_error);
}
p->data_bits++;
}
static void ot_phy_rx_worker (RX_Phy *p, int v)
{
uint32_t now, diff;
if (v == p->last_v) return;
now = dwt_read_cycle_counter();
diff = cycle_diff (p->last_cycle, now);
if (diff < 10000) return;
if (diff < 50000) {
if (! (p->half_bits & 1)) ot_phy_rx_bit (p);
p->half_bits++;
} else if (diff < 85000) {
p->half_bits++;
ot_phy_rx_bit (p);
p->half_bits++;
} else {
p->parity = 0;
p->half_bits = 0;
p->frame_error = 0;
p->data_bits = 0;
memset (p->data, 0, sizeof (p->data));
}
p->last_cycle = now;
p->last_v = v;
}
void
exti9_5_isr (void)
{
int v;
if (EXTI_PR & OT_THM_IN) {
EXTI_PR = OT_THM_IN;
v = !GET (OT_THM_IN);
#if 0
if (v)
CLEAR (OT_BLR_OUT);
else
SET (OT_BLR_OUT);
#endif
ot_phy_rx_worker (&p_thm, v);
}
if (EXTI_PR & OT_BLR_IN) {
EXTI_PR = OT_BLR_IN;
v = !GET (OT_BLR_IN);
#if 0
if (v)
CLEAR (OT_THM_OUT);
else
SET (OT_THM_OUT);
#endif
ot_phy_rx_worker (&p_blr, v);
}
return;
}
void ot_phy_rx_tick (void)
{
}
void ot_phy_rx_init (void)
{
MAP_INPUT_PU (OT_THM_IN);
MAP_INPUT_PU (OT_BLR_IN);
exti_select_source (OT_THM_IN, OT_THM_IN_PORT);
exti_set_trigger (OT_THM_IN, EXTI_TRIGGER_BOTH);
exti_enable_request (OT_THM_IN);
exti_reset_request (OT_THM_IN);
exti_select_source (OT_BLR_IN, OT_BLR_IN_PORT);
exti_set_trigger (OT_BLR_IN, EXTI_TRIGGER_BOTH);
exti_enable_request (OT_BLR_IN);
exti_reset_request (OT_BLR_IN);
nvic_enable_irq (OT_RX_IRQ);
}
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